Spray treating of web material on the paper machine



vDec. 12, 1933. E. P. ARPIN; JR 1,938,790

SPRAY TREATING 0F WEB MATERIAL ON THE PAPER MACHINE Filed April 13, 1931 2 Sheets-Sheet 1 (Edmund 0? (27pm. J1:

Dec. 12, 1933. ARPIN, JR 1,938,790

SPR AY TREATING OF WEB MATERIAL ON THE PAPER MACHINE Filed April 13, 1931 2 Sheets-Sheet 2 I. 34 I VEHZUA fdmmd -J-" I a 38 3o 5;

Patented Dec. 12, 1933 PATENT OFFICE SPRAY TREATING OF WEB MATERIAL ON THE PAPER MACHINE Edmund P. Arpin, Jr., Port Edwards, Wis. Application April 13, 1931. Serial No. 529,686

Claims.

This invention relates to a method of coating web material.

More specifically this invention relates to a process of applying Wax to a paper sheet.

i Heretofore, it has been the practice in applying materials such as paraflin, sizing, color and the like to a web material to dip the web into a bath of the treating material. I have found a more satisfactory way of applying such treat- 10 ing material which comprises spraying the material on the paper while the web is passing through the paper machine. By my method, there is no need of rearranging or redesigning the paper making machinery to adapt it to coating or other treating process, and the paper making machinery is also utilized in securely bonding the coating or treating material to the paper.

In my copending application, Serial No. 135,729, filed September 16, 1926 now U. S. Patent No. 1,880,065, granted September 2'1, 1932 of which this application is a continuation in part, I have described and claimed a device for coating paper on the paper machine which may be positioned at any point on the paper machine without redesigning or altering the paper machine. I prefer to use a spray device as described in my patent application in my present process. However, it should be understood that any device capable of projecting a stream or spray of coating material on to a traveling web may be used.

Accordingly it is an object of this invention to provide a method of treating web material which comprises spraying treating material on the web material as it is passed through an ordinary paper making machine.

It is a particular object of this invention to provide a method of coating paper with wax which comprises spraying the wax on to a preheated web of the paper while it is being passed through the paper making machinery so as to utilize the heat and pressure of the machinery in spreading and permanently bonding the wax to the paper.

Other and further important objects of this invention will be apparent from the disclosures in the specification and the accompanying drawings.

This invention (in a preferred form) is illustrated in the drawings and hereinafter more fully described.

On the drawings:

Figure 1 is a diagrammatic view of the last few drying rolls of a paper making machine,

showinga spraying device positioned-t0 direct (Cl. 9H0) a spray of coating material against the paper web as it is passed through the rolls.

Figure 2 is a diagrammatic view on a smaller scale of some of the drying rolls and the calender stack of a paper making machine showing a 80 spraying device positioned for spraying a. coating material on to the web of paper as it is passed from the drying rolls to the calender stack.

Figure 3 is a diagrammatic view of the winding reel of a paper machine showing a spraying device for spraying coating material on the surface of the paper web as it is passed over the contact roll of the winding reel.

Figure 4 isv an end elevational view of a specific type of spraying device which may be used in carrying out this invention.

Figure 5 is a longitudinal sectional view taken along the line VV of Figure 4.

Figure 6 is a cross sectional view of the spraying device, and,

Figure 7 is a detailed sectional view of one of the spraying blocks in the spraying device with parts in elevation.

As shown on the drawings:

The letter A represents the drying rolls of a l paper making machine. As shown in Figure 1, a web of paper 1 is positioned about the rolls and is held there-against by the upper and lower felts 3 and 4, respectively, which are in turn positioned around pulleys 5 and 6 respectively.

A spraying device indicated by the letter B is so arranged with respect to the web 1 passing through the drying rolls as to direct a stream of heated paraffin against the web.

The paper web passing over the drying rolls will be heated as it is customary to provide means (not shown) for heating the drying rolls. Consequently, the web after it passes the spraying device is again heated in passing over the subsequent drying rolls.

In Figure 2 there is illustrated an alternative method of my invention. In this method, the spraying device B is located between the drying rolls A and the calender stack C. Coating material from the spray device B is sprayed upon the warm web of paper whichhas recently passed through the heated drying rolls and the coated web is passed through the calender stack.

As is well known, the calender stack consists of a number. of closely mounted polished rolls between which the paper web is passed under great pressure to finish and polish the web surface. The paper web which has been sprayed with the coating material is thereby subjected to a great pressure in the calender stack and at the same time is again heated due to the friction of the rolls. These combined actions produce a uniformly impregnated paper in which the coating material is actually bonded into the surface.

Figure 3 shows another preferred arrangement of the apparatus used in carrying out my invention. In this method, the spraying device B is so arranged as to direct a spray of coating material against the web on the winding contact drum D. It has been found preferable-to direct thestream against the lower portion of the winding drum so that the paper web after it has been impregnated will pass over the drum. As it is advantageous to keep the coating or impregnating material at an elevated temperature until pressure has been applied to the coated web, the winding drum is made hollow and fitted with a pipe 8 to provide means for heating the drum. The roll of paper 10 is rotatably and slidably mounted in a guiding support, (not illustrated) and presses against the driven drum thereby exerting a pressure on the heated, impregnated web of paper on the drum as it passes under the roll.

If desired, means to exert a uniform pressure may be provided.

Figures 4 to 7 inclusive illustrate a preferred type of spraying device as is more fully described in my parent Patent No. 1,880,065. Said spray device comprises an outer hood 11 and an inner concentric hood 12 supported from said outer hood 11 by means of a plurality of angle iron straps 13. The outer hood 11 is substantially of inverted U- shaped cross section and is mounted so that its open side is directed toward the web material 1.

The inner hood of housing 12 is provided with co-extensive lower edges formed by parallel spaced flanges 14. Within the space above the inner housing 12 are positioned a pair of pipes 15, sup

.ported on the angle iron straps 13 and extending thefull length of the device. The pipes 15 which are connected at one end by a U-bend fitting 16 to a vacuum line 17 are flanged at their other end so as to be supported in the hood 11, and are fitted with caps to seal the end openings. The pipes are also provided along their length with slots 18 through which excess spraying material may be removed by suction.'

The inner hood 12 serves to house a pair of pipes 19 and 20 for compressed air, a smaller pipe 21 positioned between said pipes 19 and 20 for conducting the spraying material, and a plurality of heating coils 22. Said heating coils 22 are connected at one end by a fitting 23 which is in turn connected to a pipe line 24 leading from a source of steam supply (not shown). The compressed air lines 19 and 20 are joined at one end by a U- bend fitting 25 .to which is attached a fitting 26 which is connected by a pipe line to a source of compressed air (not shown). The pipe 21 is connected by a fitting 2'7 to a pipe line leading from a source of coating material (not shown). The coating material may be heated in a suitable container by any suitable means such as steam and is forced therefromby compressed air.

At spaced intervals along the length of the pipes 19, 20, and 21 there are mounted spray blocks 28 which are secured in the channel formed between the flanges 14. Said spray blocks 28, each comprises a member of substantially triangular cross section provided with three convergent passages 29, 30, and 31 (Figure '7). Said passages 29, 30 and 31 areinternally threaded to receive short connecting nipples 32, 33, and 34 each provided with a union 35 and connected to the pipes 19, 21, and 20 respectively. Said passages 29, 30 and 31 are each similarly restricted as at 36 and again at 37 to form capillary bores 38, intersecting as at 39 to form an enlarged orifice 40 in the lower face of each spray block.

In operation, the spray device works as follows:

Parafiin or other suitable coating material is heated in a chamber (not shown) and is forced therefrom by compressed air into the pipe 21. At the same time pre-heated compressed air from a suitable source is run into pipes 19 and 20 under a slightly higher pressure. The liquid paraffin will be forced and sucked out through the nipples 33 into the passages 30 to meet at the convergent point 39, the angular stream of compressed air flowing through the passages 29 and 31. The action of the converging air stream produces a vacuum effect upon the emerging fiuid stream and actually sucks out the fluid from its orifice. The high velocity of the converging fluid due to the restriction of the passages as at 37 to substantially capillary bore causes a very fine atomization of the coating material which issues from the orifices 40 as a fine mist. It should be noted that the orifices 40 are each flared beyond the convergence point 39' asat 41 so that the spray assumes a flattened shape in the transverse direction of the traveling web 1. It is obvious that the distance of the orifice 40 from the web 1 should be so arranged that adjacent sprays overlap slightly and thus cover the entire surface of the material to be coated.

The spraying device may be easily regulated by adjusting the pressure and temperature of the air and the relative amount of coating material fed into the spraying device. If it is desired to coat both surfaces of the web material, an additional spray device may be positioned so as to direct a spray against the under side of the web.

While I have described my process of spraying the web-material passing through the paper machine at points between the drying rolls, between the drying rolls and the calender stacks and at the winding reel, it should be understood that I may position the spray at other points on the paper machine where the bulk of the moisture has been removed from the advancing sheet without departing from the principles of my invention.

For example, in some cases, I prefer to place the spray after the calender stack and before a series of chilled rolls placed in front of the reel. Likewise, the spray may be placed between the reel stand and the rewinder or, for the application of size, color and the like, in front of the driers.

I am aware that many changes may be made and numerous details may be varied through a wide range without departing from the principles of this invention, and therefore do not propose limiting the patent granted hereon otherwise than necessitated by the prior art and the scope of the appended claims.

I claim as my invention:

1. In the manufacture of web material, on a web forming machine, the process which includes 1 spraying the web material passing through the machine while in a heated condition with a liquid treating material.

2. In the manufacture of paper in a continuous web on a paper machine the process which ineludes the application of a spray of liquid treating material to the surface of the paper sheet passing through the paper machine while in a heated condition and at a point where the bulk of the moisture has been removed therefrom.

3. In the manufacture of paper in a continuous web on a web forming machine, the process which includes the application of a spray of fluid material to a surface of the advancing sheet at a point on the machine where the bulk of the moisture has been substantially removed from the sheet, and preliminary to its passage to the reel.

4. In the manufacture of paper in a continuous web on a paper making machine, the process which includes the application of a spray of heated fluid material to a surface of the advancing sheet at a point where the bulk of the moisture has been substantially removed therefrom, and preliminary to its passage to the reel.

5. In the manufacture of paper in a continuous web on a paper making machine the process which includes spraying the paper with a fluid material as said paper is passed around a winder contact drum preliminary to being wound thereby into a roll, heating said contact drum, contacting the sprayed paper web against the heated drum and pressing the sheet between the drum and the partially wound roll.

6. The process of coating a web of fibrous material on a web forming machine during its formation with a water-repellent substance which comprises directing a fluid spray of a water-repellent substance against a surface of the web at a time in the formation of the web when the bulk of the moisture has been removed therefrom and heating the surface of the web having the said water-repellent material thereon.

7. The process of coating 9. web of fibrous material on a web forming machine during its formation with a water-repellent substance which comprises forcing a waxy substance in the form of a warm fluid spray against a surface of the said web at a time in the formation of the web when the bulk of the moisture has been substantially removed from the web to thereby form a water-repellent film on the said web surface, and chilling said film.

8. In the manufacture of paper in a continuous web on .a paper machine, the process of waxing which includes the application of a spray of fluid wax to a surface of the advancing sheet of the material which has been warmed by passage through the machine and subsequently heating and compressing the sheet material as it is further passed through the machine.

9; The process of coating a web of fibrous material on a web forming machine during its formation with a water repellent substance which comprises forcing a waxy substance in the form of a warm fluid spray against the surface of the said web while it is being passed through a number of heated rolls in the ordinary paper making machine.

10. The process of spray treating a web material on a paper machine which comprises heating said web material, spraying the surface of the heated web with a treating fluid and finishing the sprayed surface while the web is still in 

